1. Field of the Invention
The present invention relates to a multi-program processing system and a rollback method for a file used therefor, and in particular related to a rollback method for a file in a multi-program processing system in which a plurality of programs can simultaneously operate.
2. Description of the Related Art
Conventionally, a plurality of programs can operate simultaneously in a multi-program processing system, and there are block exclusion and rollback as a function for protecting an important file against reference and update from the plurality of programs when one file is referred to and updated simultaneously by the plurality of programs.
The block exclusion is processing for preventing a certain file that is being referred to and updated by a program from being referred to and updated by another program until the reference and update by the certain program is finished.
In addition, the rollback is processing, in the case when the processing cannot be normally completed due to the occurrence of some abnormality during operation of a certain program, that is, the case in which a deadlock or an abnormal termination occurs, for stopping operations relating to the operation of the program to return information related thereto to a state before operation.
However, since any program is equally handled in the block exclusion in the above-mentioned conventional file protecting function. Therefore, when the rollback is performed due to a deadlock or an abnormal termination of a program, even if there is a block required next, the block cannot be referred to and updated until completing the rollback if the block is the block being an object of the rollback.